ECAP is a key negative regulator mediating different pathways to modulate salt stress-induced anthocyanin biosynthesis in Arabidopsis
ECAP is a key negative regulator mediating different pathways to modulate salt stress-induced anthocyanin biosynthesis in Arabidopsis
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ECAP 是介导拟南芥中盐胁迫诱导的花青素生物合成的不同途径的关键负调节因子。
DOI：
10.1111/nph.17937
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发表时间：
2022-01-13
期刊：
影响因子：
9.4
通讯作者：
Fu, Ying
中科院分区：
文献类型：
--
作者：
Li, Changjiang;Shi, Lei;Fu, Ying
花色苷是一类具有抗氧化活性的植物黄酮类化合物，在植物体内受到各种生物和非生物胁迫时，花色苷能有效地清除自由基和活性氧。然而，盐胁迫诱导花青素苷生物合成的调控机制尚不清楚。利用分子和遗传学技术，我们证明了ECAP在拟南芥盐响应花色素苷生物合成途径中的关键作用。已知ECAP、JAZ 6/8和TPR 2形成转录抑制因子复合物，负调控茉莉酸（JA）响应的花青素积累。在这项研究中，我们证明，在中度盐胁迫下，花青素的积累是部分依赖于JA信号，降解JAZ蛋白，但不是ECAP。更有趣的是，我们发现高盐度而不是中等盐度通过26 S蛋白酶体途径诱导ECAP降解，并且该过程不依赖于JA信号。进一步的分析表明，ECAP与MYB 75（一种激活花青素生物合成基因的转录因子）相互作用，并在高盐条件下抑制其转录活性。研究结果表明，植物在不同盐胁迫水平下采取不同的调控策略来微调花色素苷的积累，进一步阐明了花色素苷生物合成在植物发育和对环境胁迫响应过程中的复杂调控。
Anthocyanins are a subgroup of plant flavonoids with antioxidant activities and are often induced by various biotic and abiotic stresses in plants, likely to efficiently scavenge free radicals and reactive oxygen species. However, the regulatory mechanisms of salt-stress-induced anthocyanin biosynthesis remain unclear. Using molecular and genetic techniques we demonstrated key roles of ECAP in differential salt-responsive anthocyanin biosynthesis pathways in Arabidopsis thaliana. ECAP, JAZ6/8, and TPR2 are known to form a transcriptional repressor complex, negatively regulate jasmonate (JA)-responsive anthocyanin accumulation. In this study, we demonstrated that under moderate salt stress, the accumulation of anthocyanins is partially dependent on JA signaling, which degrades JAZ proteins but not ECAP. More interestingly, we found that high salinity rather than moderate salinity induced the degradation of ECAP through the 26S proteasome pathway, and this process was independent of JA signaling. Further analysis revealed that ECAP interacts with MYB75 (a transcription factor activating anthocyanin biosynthetic genes) and represses its transcriptional activity in the absence of high salinity. Our results indicated that plants adopt different strategies for fine-tuning anthocyanin accumulation under different levels of salt stress, and further elucidated the complex regulation of anthocyanin biosynthesis during plant development and responses to environmental stresses.